galvanized steel equipotential bonding grid installed by mistake

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bshirley

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If someone made a mistake and used 16ga Galvanized steel mesh, 4' wide with 2"x3" holes instead of copper when pouring concrete and bonded too it in 4 places from the hot tub which is a completely self contained acryllic tub what would the difference in the surface voltage that could be experienced by someone on the concrete if the hot tub had a 100amp 240v supply?
How would this differ from a copper equipotential bonding grid?
 
I am not certain but it sounds significantly different. If you are under the 2011 code you may not need a grid at all. There was a TIA issued in March on this.

A Tentative Interim Amendment is tentative because it has not been processed through the entire standards-making procedures. It is interim because it is effective only between editions of the standard. A TIA automatically becomes a proposal of the proponent for the next edition of the standard; as such, it then is subject to all of the procedures of the standards-making process.
1. Revise 680.42(B) to read as follows:
680.42(B) Bonding. Bonding by metal-to-metal mounting on a common frame or base shall be permitted.
Exception No. 1: The metal bands or hoops used to secure wooden staves shall not be required to be bonded as required in 680.26.
Exception No. 2: A listed self-contained spa or hot tub that meets all of the following conditions shall not be required to have equipotential bonding of perimeter surfaces installed as required in 680.26(B)(2):
(1) Is installed in accordance with manufacturer’s instructions on or above grade.
(2) The vertical measurement from all permanent perimeter surfaces within 30 horizontal inches (76 cm) of the spa to the top rim of the spa is greater than 28 inches (71 cm).
Informational Note: For further information regarding the grounding and bonding requirements for self-contained spas and hot tubs, see ANSI/UL 1563 – 2009, Standard for Electric Spas, Equipment Assemblies, and Associated Equipment.
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Clarification

Clarification

The hot tub is below grade, it is sunk into the ground and surrounded by a concrete slab. The slab doesn't contain reinforced steel as it has a fiber mesh and 5000 psi concrete. Any way to get around it other than ripping out the entire slab and radiant heat and starting again?

Would it be incorrect to assume that the maximum voltage someone could be subjected too is around 9 volts anyway? Isnt the code really for external swimming pools with overhead power lines and commercial pools with massive 3 phase supply. Surely a small residential 240volt 100 amp supply couldnt actually do much damage to someone standing on the side of a pool
 
bshirley said:
Surely a small residential 240volt 100 amp supply couldnt actually do much damage to someone standing on the side of a pool
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Surely Shirley you are joking right. 30 volt can kill you when you are in a pool. Are you licensed to do this work or does your area not require a license.

There does not need to be steel in the concrete to require the equipotential bond. It does not need to be a grid either.
 
Outside of the pool

Outside of the pool

Equipotential is about someone standing outside the pool on the concrete not in the pool full of highly conductive water
 
bshirley said:
Again, Equipotenital bonding is about someone stood "BESIDE" a pool not "IN" a pool
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Yes but it is also involves touching the water or other grounded parts of the tub. The tub is recessed in the concrete and one can easily touch the decking (concrete) and the water at the same time.

You did not answer my question in my second response and it seems like you are adamant in your view. I think I will close this thread before someone gets hurt or until the op responds to me.
 
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